Method of sealing hydrocarbon conversion housings



P 1951 L. J. KELLY 2,566,896

METHOD OF SEALING HYDROCARBON CONVERSION HOUSINGS Filed Dec. 31, 194'? 2 Sheets-Sheet 1 INVENTORV Zauzl/ cf Kelly ATTORN EY Sept. 4, 1951 J. KELLY 2,566,895

METHOD OF SEALING HYDROCARBON CONVERSION HOUSINGS Filed Dec. 51, 1947 2 Sheets-Sheet 2 INVENTOR.

Laziz'a c1 A2117 Patented Sept. 4, 1951 METHOD OF SEALING HYDROCARBON CONVERSION HOUSINGS Louis J. Kelly, Tenafly, N. J assignor to Houdry Process Corporation, Wilmington, Del., a corporation of Delaware Application December 31, 1947, Serial No. 794,956

3 Claims. (Cl. 196-52) My invention relates to a method of sealing hydrocarbon conversion housings to prevent pas sage of hydrocarbon vapors upwardly through the conduit which supplies regenerated contact vertical conduit in the general manner described above. In accordance with the detailed aspect of my invention to which, however, the'invention is not necessarily to be limited the elevator housmaterial' thereto; 5 ing last named forms a sealed path including the In hydrocarbon conversion systems of known aforesaid vertical and downwardly inclined concharacter; contact material is admitted to a conduits. As the operation proceeds, the described version or reaction housing after gravitating passealing medium is admitted to the lower, end of sage through a vertical conduit which opens said vertical conduit for passage through this through the top housing wall, movement of this in sealed path in counter-current relation 'with regravitating contact material being restricted or spect to the contact material gravitating thereimpeded so that it moves through said conduit through whereupon it is vented to the atmosin solid column fashion. After admission to the phere. Further in accordance with the invenhousing, the contact material gravitates theretion, the aforesaid sealed path is traversed by through in solid bed fashion and, as the conver lo a gaseous sealing medium throughout'thelength sion operation proceeds, a hydrocarbon vapor thereof and, in any-suitablemanner, said sealing pressure is developed interiorly of the upper housmedium, in the inlet or upper end of the con-' ing portion above said bed. In order to prevent version or reaction housing, is maintained under passage of these vapors upwardly through the pressure slightly exceeding that of the hydroaforesaid vertical conduit, it iscustomary for a carbon vapors for the useful purpose described. gaseous sealing medium to be admitted to said Various other objects and advantages of my upper housing portion where, for the purpose invention will become apparent from the followstated, it is maintained at pressure slightly exing detailed description. ceeding that of the hydrocarbon vapors. The My invention resides in the method of sealing gaseous sealing medium flows upwardly through 2 conversion housings, arrangements and features the vertical conduit, counter-current as regards of the character hereinafter described and the descending contact material, and at some claimed. location beyond the upper end thereof is vented For an understanding of my invention and for to the atmosphere. As a result, depending on an illustration of one form of apparatus utilizabl'e known factors, it often isnecessary for said verfor practicing the invention, reference is to 'be tical conduit to have height substantially greater had to the accompanying drawings, in which: than that required by other apparatus which is Fig; l is a plan view diagrammatically illustratassociated with the described conversion or reing a conversion-regenerating system of the inaction housing to form a complete conversionvention; regenerating system. This disadvantage is over- Figs. 2 and 3 are elevational views, partly come in a novel manner as hereinafter described. broken away, taken on the respective lines 2'- 2 When contact material gravitates' through a and 3--3 of Fig. 1; conversion housing in solid bed fashion as re- Fig. 4 is an elevational view, partly in section, ferred to above, a regenerating housing is usually taken on the line 4-4 of Fig. l; disposed'adjacent thereto. By asuitable elevator 40 Fig; 5 is an enlarged, vertical sectional view, r n em n sp C n m ri l from the partly in elevation, showing the lower portion conversion housing is raised above the inlet level of the regenerating housing of Fig. 4; I of the regenerating housing for gravitating move- Fig. 6 is an enlarged, vertical sectional view. ment therethrough, and regenerated contact mapartly in elevation, showing the lower portion of terial, after passage from thela'st named housing the elevator housing illustrated in Fig. 4; by way of a downwardly inclined conduit through Fig. 7 is an enlarged elevational view, partly which it moves in solid column fashion, is raised broken away, showing the lower portion of the through a suitableelevator housing to a location conversion housing and its outlet conduit; and substantially above the inlet level of the conver- Fig. 8 is an enlarged view, partly broken-away, sion housing for admission thereto by way of showing a detailed feature of the invention.

Referring to Figs. 1-4 inclusive, I have shown a conversion system which, except as hereinafter described, may be such as is conventionally used for converting hydrocarbons in the presence of contact material adapted, during on-stream operation, to gravitate through a conversion zone and, during regeneration, to gravitate through a regenerating zone. Thus, as illustrated, the aforesaid system may comprise a housing C which defines the conversion zone, a housing B which defines the regenerating zone and vertical elevators- S and R'--utilizable; respectively, for conveying spent and regenerated contact material from lower to upper levels.

The conversion housing C and associated apparatus may be of any suitable character. ,As shown particularly in Fig. 4, there is supported at the top of the housing C a hopper I to which regenerated contact material M-is admitted continuously in the manner hereinafter described. Depending from and communicating with the hopper l are a plurality of pipes 2 through which the contact material passes to form a gravitating bed of contact material, the lower surface of which may be definedjby a tube sheet 3 horizontally supported in the lower portion of the housing C. As the conversion operation proceeds, contact material M is admitted to the housing C as described above and moves downwardly therethroughunder the influence of gravity while a deposit of carbonaceous material is formed thereon. v

' Any suitable arrangement may be utilized for discharging the spent contact material M from the housing C. To this end, and as diagrammatically indicated, a plurality of spaced tube sheets 4 may be secured to the interior surface of the lower end portion of the housing C below the aforesaid tube sheet 3, the extreme lower end portion of saidhousing-C, preferably, being conical as illustrated. A plurality of suitably spaced tubes or pipes 5 open through and depend from each of the tube sheets 3 and 4. As known in the art, the tubes 5 on successively lower tube sheets progressively decrease in number and the internal diameter thereof progressively increases whereby the contact material gravitates through the lower conical end portion of thehousing C so as to reach and traverse a main discharge pipe or conduit 6 which should .be suitably inclined as illustrated. In known contact material through said'conduit 6 for the purpose hereinafter described.

When hydrocarbon material is to be cracked in the housing C, the contact material M hereinbefore referred to should be catalytic in character and. the temperature thereof, upon admission to the-housing C, should range between 800 F. and 1000" F. or higher for example, about 900 F. Any suitable kind of catalytic contact material may thus be utilizedsuch, for example, as activated clay pellets, or synthetic silicaalumina pellets or,beads, etc. having suitable major dimensions'such as between 1% and A of an inch. Other suitable catalysts for cracking include synthetic plural oxide compositeasilicious or non-silicious in character and containing for example, zirconia, alumina, or beryllia. In lieu of a cracking oper-ation, other types of conversion operations such, for example, asone wherein hydrocarbon material of the character referred to below is desulphurized under known conditions with catalytic contact material of the general character referred to above, or equivalent. Or, reforming or dehydrogenation of naphthas or other normally liquid hydrocarbons may be effected in the presence of the above or other desired types of catalyst, certain of which are well known in the art. In lieu of the conversion operations described above, heavy hydrocarbon material may be vaporized and viscositybroken in the presence of inert contact material of known character.

-- During operation with suitable cracking contact material, vapors such, for. example, as vaporized gas oil, naphtha, or lighter hydrocarbons having suitable elevated temperature, as in a range from 850 F. to 950 F., are admitted continuously by a pipe 9 to the housing C above the upper surface of the bed of contact material. In the manner hereinafter described, these hydrocarbon vapors, as the conversion operation proceeds, pass concurrently as regards the contact material gravitating through the housing C and, adjacent the lower end of said housing, any suitable arrangement may be provided for disengaging converted vapors from the contact material. To this end, asv diagrammatically indicated, the aforesaid tube sheet 3 may support a plurality .of tubes [0 which .up-.

stand therefrom and open therethrough, the tubes ID supporting a plurality of suitably ar ranged channel members I I, orequivalent, which are disposed in inverted relation so that, in known manner, they may be utilized for disena gagement of vapors from-the contact material,

the vapors thereafter entering the tubes lfljby ner, and by suitable means, not shown, a suitable gaseous medium, such as steam orflue gases is admitted to the lower portion of the housing C, below the pipe [2 andunder pressure above that existing at thelevel thereof, to prevent passage of hydrocarbon vapors through the conduit 8.

The lower end of .the aforesaid conduit 6 opens into the lower end of the housing l3 for the elevator S- which may be of conventional character orotherwise as may be desirable. As indi cated in Fig. 2, the elevator S may comprise a pair of side-byside, endless carriers M which are supported --by suitably mounted upper and lower rotatable-members l5.- The carriers M are operated continuously by suitable mechanism, not shown, and they have elevator buckets l6 secured thereto in suitable manner. The buckets t6 receive :the spent contact material from the lower end of the conduit 6 and elevate the same. to the upper end of the, elevator housing 13 where it is discharged into the-:upper end of a downwardly inclined conduit 11 which is suitably connected, in communicating relation, with said upper end of the housing 13. h a

The spent contact material which has been elevated as describedimmediately above gravitates through the conduit l1 and, in any desired manner, is admitted to the upper endof the regenerating housing B which together with its associated apparatus may be of conventional character or. otherwise as may. be desirable...-

Thus, as shown in Figure 4, the aforesaid conduit I! may extend through the top wall of the housing Bat the center thereof so as, to discharge the spent contact material on a tube sheet l8 horizontally secured in the top portion of said housing B. Opening through and depending from this tube sheet I8 are a plurality of tubes I9 through which the spent contact material, by action of gravity, passes into and then through the regenerating zone proper which may have disposed therein an upper disengager 20 below which is disposed an upper engager 21 having an upper set of cooling coils 22 disposed therebelow.

The disengager 20 and engager 2| may be of any suitable construction and, as herein diagrammatically shown, each may comprise a horizontal pipe 23 fixed transversely in thehousing B and intersecting the longitudinal axis thereof, each pipe 23 carrying a plurality of inverted channel members 24 extending horizontally from opposite respective sides thereof.

As known in the art, the housing B, throughout the height thereof, may carry sets of disengagers 20 and engagers 2| alternately arranged with a group of cooling coils 22 disposed between each engager and the adjacent disengager as shown in Fig. 4. By each of the engager pipes 23 and the associated channel members 24, air or other suitable regenerating medium is engaged with the gravitating contact material to burn carbonaceous material therefrom with consequent elevation in temperature thereof, the re sulting flue gases being disengaged from the contact material at the channel members 24 of the disengager pipes 23 and passed from the housing B by way of the pipes last named. In known manner, a suitable cooling medium, such as water, fused salts or the like is passed through the coils 22 in order to lower the temperature of the contact material after it passes each engager 2|.

Any suitable draw-off arrangement may be utilized for discharging the regenerated contact material from the housing B. Preferably, however, this arrangement is of the character disclosed in pending application Serial No. 734.589, filed March 14, 1947.

As indicated in Fig. 5, the aforesaid arrangement comprises a horizontal baiile plate 25 having a plurality of symmetrically arranged funnels disposed therebelow, said baffle plate 25 compris ing a plurality of symmetrically arranged vertical passages, groups of which communicate with the respective funnels 26. The funnels 25, in

turn communicate with vertical pipes 21 which .1. 'form groups, of which consists of four pipes,

all of these groups beingsymmetrically related to each other. Each pipe 21 comprises and com municates with an angular, downwardly extending pipe section, the pipe sections of each group of pipes 21 extending toward a common center where, at a common level, they communicate with a vertical pipe 28 all of which are supported by the aforesaid bottom wall of the housing-B. The pipes 23 form symmetrical groups consisting of four pipes each, each pipe 28 comprising and COil1- municating with an angular, downwardly ex tending pipe section, the pipe sections of each group extending toward a common center Wher at a common level, they communicate with a. vertical pipe 29. The pipes 29 form a single groin of pipes, each of which comprises and communicates with an angular downwardly extendin pine section, all of the latter, at a common level, communicating with a single main pipe or conduit 38,

inbefore described housing C.

6, the longitudinal axisof which coincides with the longitudinal axis of. the housing B.

The regenerated contact material gravitates from the regenerating zone by way of the described passages in the baffie plate 25 and thereafter gravitates through the described pipes and pipe sections and eventually reaches the main pipe 30. All of the contact material gravitates through said main pipe 30 and then through a conduit 3| which should be suitably inclined in the manner hereinafter described. A valve 32 mounted on a shaft 33, Fig. 6, and controlled as hereinafter described is utilized to restrict gravitating flow of the regenerated contact material through said conduit 3| for the purpose described below.

The lower end of the aforesaid conduit 3| opens, in sealed relation, into the lower end of the housing 34 for the aforesaid elevator R. In accordance with the invention, the housing 34 defines a passage which is sealed from the atmosphere so that, in the manner hereinafter described, pressure in excess of that of the atmosphere may be maintained therein, such excess pressure, however, being substantially the same throughout the height of said housing 34.

If desired, the elevator R, the same as the'hereinbefore described elevator S, may comprise a pair of side-by-side, endless carriers l4 supported by suitably mounted upper and lower rotatable members I5, the carriers being continuously operated by suitable mechanism, not shown, and having elevator buckets l6 secured thereto. The buckets ii of the elevator R receive the regenerated contact material from the lower end of the conduit 3| and elevate the same to the upper end of the sealed elevator housing 34 where it is discharged into the upper end of a downwardly inclined conduit 35 which is suitably connected in communicating, sealed relation with the upper end of the housing 34.

The regenerated contact material which has been elevated as described immediately above gravitates through the conduit 35 from which it enters a receptacle 35 which, preferablyand in accordance with the invention, is positioned at the highest practical level while permitting the conduit 35 to have suflicient slope'to obtain proper gravitational movement of the contact material therethrough. After admission to the receptacle 36, the contact material gravitates continuously therethrough' after which it enters and gravitates through a conduit portion 31a and then through a conduit 31 which communicates with the herehopper l at the top of the During operation of the disclosed system, the position of the valve 1 may be controlled automatically in. known manner, for example as disclosed in application Serial No. 719,730, filed January 2, 1947, now Patent No. 2,528,537 in response to change in level of the upper surface of the contact material in the receptacle 35. By the valve 1, gravitational movement of the contact material along a path extending from the level thereof in the receptacle 36, through the conduit", thehousing C and the portion of the pipe 6 above said valve 1 is restricted or impeded pipe l2 and such equipment as is connected in circuit therewith. In order to produce the desired concurrent flow of the hydrocarbon vapors with respect to the gravitating contact material in the housing C, it necessarily follows, then, that said hydrocarbon vapors should be admitted to the housing C at a pressure sufficient to overcome the aforesaid pressure drop to suitable degree. At the same time, the operation should be conducted under conditions such that the hydrocarbon vapors do not pass upwardly through the pipe 31.

To this end, a suitable gaseous sealing medium, such as flue gases, steam, or equivalent, is admitted continuously to'the top of the housing C above the hopper I by way of a pipe la, Fig, 4, at a pressure exceeding that at which the hydrocarbon vapors are admitted to the housing C by way of the pipe 9. Due to this operation, the hydrocarbon vapors are prevented from' passing upwardly through the vertical conduit 31 and the major portion, usually, of the sealing medium passes along the above described sealed path and then'to theatmosphere in the manner hereinafter described. Also, by the described operation, the hydrocarbon vapors are caused to flow in desired concurrent relation as regards the gravitating contact material in the housing C. I

Initially, the aforesaid major portion of the sealing medium passes, counter-current to the descending contact material, upwardly along that part of the sealed path defined by the vertical conduit 31, the receptacle 36 and the pipe 35. By reason of the described restricted or impeded flow of the contact material traversing the vertical conduit 31 (which defines and is an example of one downwardly extending path portion as set forth in claim language) a pressure gradient is effective throughout a vertical distance d, Fig. 4.

In connection with theforegoing, the pressure gradient through the receptacle 36 is insignificant by reason of the substantially larger diameter thereof compared with that of the pipe 31. Moreover, the contact material traversing the pipe 35 falls freely under the influence of gravity except for frictional retardation on the interior surface thereof "and, accordingly, the pressure gradient therethrough is nil or substantially so.

After passage of the aforesaid major portion of the sealing medium along'that'part of the sealed path described'above, said sealing medium, at reduced pressure, enters and, at substantially constant pressure, passes downwardly throughthe housing 34 of the elevator Rwhich, as stated, is sealed from the atmosphere. Thereupon, as described below, the sealing medium leaves thebottom of said elevator housing and traverses the remaining part of the sealed path.

During operation of the disclosed system, the

valve 32, Figs. "4 and 6, restricts or impedes gravitational movement of the contact material along a path extending from the level thereof at the top of the housing B, through the drawoff system illustrated in Fig. 5 and then'through that portion of the pipe 3| above said valve 32.

Should it become necessary; the positionof this valve may be changed manually in order to .vary

the rate of movement of the gravitating contact material lastnamed. Due to the described actionof the valve 32, the contact material moves in solid column fashion throughout the'length of the path described immediately above.

" As stated above, the major portion of the sealing medium leaves the bottom of the sealed elevator housing 34-. Thereafter, this sealing medium passes upwardly through the pipe 3| and, above the valve 32, traverses the remaining part of the sealed path, namely, that portion of the pipe 3| above said valve 32, the draw-off system shown in Fig. 5'and the bed of contact material in the housing B below the lowermost disengager 20, said gaseous medium, as the operation proceeds, passing to the atmosphere by Way of the channel members 24 and the pipe 23'of said last. named disengager. By reason of the described restricted or impeded flow of the contact material along the sealed path last noted (which is an example of another downwardly extending path portion as set forth in claim language), a pressure gradient is effective through a vertical distance d1, Fig. 4. 1

In prior practice, as regards a conversion-regenerating system of the general character herein'disclosed, it is customary for the regenerated contact material to pass from the upper end of its elevator by way of an inclined pipe which communicates with a surge hopper communicating, in turn, with a vertical pipe which extends into the upper end of the. conversion housing. .This pipe has vertical height below the surge hopper sufficient for the intended purpose With this prior art arrangement, the vertical height of the aforesaid pipe together with that of the surge hopper and the inclined pipe admitting contact material thereto determines the height of the elevator which supplies regenerated contact material to said last'named inclined pipe. Aside from this, the over-all height spent contact material .may be passed thereto by way of the sloping pipe provided for this purpose. Often, in prior art practice, the required vertical height of the aforesaid pipe causes the height of the elevator for the regenerated contact material to be substantially greater, for example, twenty-five to fifty feet greater than is required by any other part of the system.

In accordance with my invention and by utilization of the path portion indicated at d1, Fig. 4, the necessary height of theelevator forthe regenerated contact material may be substantially reduced compared with prior practice as referred toabove. Thus, for example and as shown on the drawing, the height of the elevator last named may be the same or substantially the same or even less than that of the elevator which supplies spent contact material to the regenerating housin bviously, substantial reduction in height of the elevator for the regenerated contact material as referred to above is desirable because reducing the expense of installation and maintenance. Again, decreased elevator height renders the prospect of continuous operation more favorable and this, of course, is highly desirable. By my invention, the over-all height of the conversion-regenerating system is reduced to substantial extent and this is desirable because reducing the expense, simplifying the construction and operation, and lessening the hazard of air travel particularly when the system is located in the immediate vicinity of an airport.

As indicated in Fig. 4, a part of the sealed path indicated by the distance di extends upwardly through the described draw-off arrangement and includes the lower portion of the regenerating housing B. However, the invention is not to be I thus limited. Thus, for example, should it be desirable to shorten the length of the path indicated by the distance (11, the pipe 3|, in a suitable location, may be provided with a suitable vent to the atmosphere.

From one of its broader aspects, the invention relates to utilization of the sealed elevator housing 34 or equivalent which extends between and communicates with separate portions of said paths. These portions may be of suitable character as desired and not necessarily as herein illustrated. However, ordinarily and as disclosed, it is desirable for one of these path portions to be defined by a vertical conduit 37 through which regenerated contact material gravitates into a conversion housing while flowing in a restricted or impeded manner. Again, in accordance with another broad aspect of the invention, this vertical conduit 31 may be omitted and, if so, the contact material from the upper end of the sealed elevator housing 34 may be admitted to the conversion housing C (or a suitable surge hopper) in suitable manner, for example by way of a down wardly inclined pipe through which said contact material falls freely under the influence of gravity except for frictional retardation on the interior surface thereof. With an arrangement of this character, the lower end of said elevator housing may communicate in sealed relation with the lower end of the part portion above the valve 32 which may have proper length for the intended purpose. Or the lower end of said elevator housing may communicate with one or more downwardly extending path portions through which the contact material gravitates in solid column fashion.

It was hereinbefore stated that the receptacle 36 is located, preferably, at the highest practical level while permitting the conduit to have sufficient slope to obtain proper gravitational movement of the contact material therethrough. The invention, however, is not to be so limited. Thus, as indicated in Fig. 8, the conversion housing C may have associated therewith a vertical pipe 40 which communicates with a surge hopper 4| from which an inclined pipe 42 extends upwardly to the top of the elevator R. With this arrangement, regenerated contact material traversing the pipe 42 falls freely under the influence of gravity except for frictional retardation on the interior surface thereof. Thereafter, this contact material gravitates in solid column fashion through the surge hopper 4| and the vertical pipe 40. This arrangement, except as regards the height of the vertical pipe 40, corresponds with the prior art arrangement previously described and, as will be understood, a pressure gradient is effective throughout a vertical distance d2 which is less than as disclosed in Fig. 4.

When contact material gravitates in an impeded or restricted manner through an inclined pipe, it is necessary for this pipe to be related to a horizontal plane by an angle of at least approximately 45 degrees. As regards the disclosed system, the foregoing applies to the pipes 6, 3| and the inclined portion 31a of the pipe 31. This relation is shown in Figs. 3 and 4 with respect to the pipes 6, 3| and in Fig. 2 with respect to the pipe portion 31a. When contact material traversing an inclined pipe falls freely under the influence of gravity except for frictional retardation on the interior surface thereof, the angle of inclination may be somewhat less than as stated above. This applies to the described pipes ll, 35 and 42.

It will be understood that the invention is not 10 to be limited to the disclosed conversion opera-' tion which involves admission of hydrocarbon vapors to the top of the housing C for passage therethrough in concurrent relation as regards the gravitating contact material. Obviously, the invention is applicable to conversion operations of other types such, for example, as one wherein hydrocarbon vapors pass counter-current as regards the gravitating contact material or wherein the charge, partly in liquid phase, is admitted into the upper portion of the conversion housing for downward passage therethrough along with hydrocarbon vapors.

It shall understood that, except as set forth in claim language, there is to be no limitation of the invention to the disclosed arrangement involving admission of the gaseous sealing medium to the housing C by way of the conduit la. Thus, within a broader aspect of the invention, the gaseous sealing medium may be admitted to the described sealed path at any desired location provided, first, that said gaseous medium is present throughout the length thereof so as to be maintained, in the upper part of the housing C, at pressure slightly greater than that of the hydrocarbon vapors and, second, that it passes through the solid column contact material gravitating through one or more of the described path portions having sufficient length for the intended purpose.

Each of the appended claims includes a reference to a sealed path arrangement such, for example, as said path portions and the part of said path connecting them together being sealed from the atmosphere throughout the length thereof. It shall be understood that such references are intended to be descriptive of sealed path arrangements wherein the pressure of the gases therein is maintained in excess of that of the atmosphere even though some of the gases may pass to the atmosphere, for example, through a throttled vent.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made Without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim as my invention:

1. In a hydrocarbon conversion system in which solid contact material is passed cyclically through separate zones wherein said material is contacted with different gases under different gaseous pressures, the method of transferring said contact material between said zones while maintaining a substantial gas seal therebetween which comprises the steps of passing said contact material from the zone of lower gaseous pressure downwardly in a confined path as a compact moving column, elevating said contact material from the lower end of said column through an elongated confined path wherein the gaseous pressure is substantially .uniform throughout, passing all said elevated contact material downwardly in a confined path from the upper end of said elongated confined path as a second compact moving column, introducing said contact material at the lower end of said second column into the contact zone of higher pressure, and introducing a gaseous sealing medium at a low point in said second column to provide a pressure thereat greater than the pressure in said contact zone of higher pressure, said confined paths and said elongated confined path providing a single continuous passage for countercurrent flow of said material and said sealing medium between said zones.

2. A method as defined in claim 1 wherein said zone of higher pressure constitutes a reaction zone for the conversion of said hydrocarbons and vthe zone of lower pressure constitutes a regeneration zone for reactivating said contact material, and wherein said gaseous sealing medium is discharged to the atmosphere from the lower region of said regeneration zone.

3. A method as defined in claim 1 wherein said elongated confined path is of sufiicient crosssection area to permit the elevation of said contact material therethrough in separated mass REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date v 2,443,180 Bergstrom June 15, 1948 2,443,412

Bergstrom et al. June 15, 1948 

1. IN A HYDROCARBON CONVERSION SYSTEM IN WHICH SOLID CONTACT MATERIAL IS PASSED CYCLICALLY THROUGH SEPARATE ZONES WHEREIN SAID MATERIAL IS CONTACTED WITH DIFFERENT GASES UNDER DIFFERENT GASEOUS PRESSURES, THE METHOD OF TRANSFERRING SAID CONTACT MATERIAL BETWEEN SAID ZONES WHILE MAINTAINING A SUBSTANTIAL GAS SEAL THEREBETWEEN WHICH COMPRISES THE STEPS OF PASSING SAID CONTACT MATERIAL FROM THE ZONE OF LOWER GASEOUS PRESSURE DOWNWARDLY IN A CONFINED PATH AS A COMPACT MOVING COLUMN, ELEVATING SAID CONTACT MATERIAL FROM THE LOWER END OF SAID COLUMN THROUGH AN ELONGATED CONFINED PATH WHEREIN THE GASEOUS PRESSURE IS SUBSTANTIALLYI UNIFORM THROUGHOUT, PASSING ALL SAID ELEVATED CONTACT MATERIAL DOWNWARDLY IN A CONFINED PATH FROM THE UPPER END OF SAID ELONGATED CONFINED PATH AS A SECOND COMPACT MOVING COLUMN, INTRODUCING SAID CONTACT MATERIAL AT THE LOWER END OF SAID SECOND COLUMN INTO THE CONTACT ZONE OF HIGHER PRESSURE, AND INTRODUCING A GASEOUS SEALING MEDIUM AT A LOW POINT IN SAID SECOND COLUMN TO PROVIDE A PRESSURE THEREAT GREATER THAN THE PRESSURE IN SAID CONTACT ZONE OF HIGHER PRESSURE, 